Electric motor

Abstract

An electric motor includes a rotor and a stator. The stator includes a first stator segment including a first annular back portion, a first tooth extending radially inward from the first annular back portion, a first flange extending away from the first tooth, a first insulation portion at least partially covering the first annular back portion, the first tooth, and the first flange, and a first coil wound around the first tooth. The stator also includes a second stator segment separate from the first stator segment and axially coupled to the first stator segment, the second stator segment including a second annular back portion, a second tooth extending radially inward from the second annular back portion, a second flange extending away from the second tooth and toward the first flange, a second insulation portion at least partially covering the second annular back portion, the second tooth, and the second flange.

What is claimed is: 
     
         1 . An electric motor comprising:
 a rotor;   a stator including
 a first stator segment including
 a first annular back portion, 
 a first tooth extending radially inward from the first annular back portion, 
 a first flange extending away from the first tooth, 
 a first insulation portion at least partially covering the first annular back portion, the first tooth, and the first flange, and 
 a first coil wound around the first tooth, and 
 
 a second stator segment separate from the first stator segment and axially coupled to the first stator segment, the second stator segment including
 a second annular back portion, 
 a second tooth extending radially inward from the second annular back portion, 
 a second flange extending away from the second tooth and toward the first flange, 
 a second insulation portion at least partially covering the second annular back portion, the second tooth, and the second flange, and 
 a second coil wound around the second tooth. 
 
   
     
     
         2 . The electric motor of  claim 1 , wherein the first annular back portion and the second annular back portion are both ring-shaped. 
     
     
         3 . The electric motor of  claim 1 , wherein:
 the first stator segment further includes a third tooth extending radially inward from the first annular back portion, and   the second tooth is positioned between the first tooth and the third tooth.   
     
     
         4 . The electric motor of  claim 3 , wherein the first stator segment further includes a third coil wound around the third tooth, and a first crossover portion extending between and electrically connecting the first coil and the third coil. 
     
     
         5 . The electric motor of  claim 4 , wherein:
 the first annular back portion includes a first axial end surface;   the first insulation portion includes a first insulation end cap covering the first axial end surface;   the second annular back portion includes a second axial end surface;   the second insulation portion includes a second insulation end cap covering the second axial end surface;   the first crossover portion is routed adjacent the second insulation end cap;   the first coil has a first wire end portion;   the third coil has a second wire end portion; and   the first wire end portion and the second wire end portion are located adjacent the first insulation end cap.   
     
     
         6 . The electric motor of  claim 1 , wherein the stator further includes a third stator segment including
 a third annular back portion,   a third tooth extending radially inward from the third annular back portion,   a third flange extending away from the third tooth,   a third insulation portion at least partially covering the third annular back portion, the third tooth, and the third flange, and   a third coil wound around the third tooth; and   
       wherein the first annular back portion, the second annular back portion, and the third annular back portion are all ring-shaped. 
     
     
         7 . The electric motor of  claim 1 , wherein the first coil includes a plurality of progressive turns including a first turn, a plurality of intermediate turns, and a final turn, and wherein the final turn has a greater cross-sectional length than the first turn. 
     
     
         8 . The electric motor of  claim 7 , wherein the first turn and the final turn each have an equal cross-sectional width measured perpendicular to the cross-sectional length. 
     
     
         9 . The electric motor of  claim 1 , wherein:
 the first insulation portion includes
 a first back insulation portion covering the first annular back portion, 
 a first tooth portion covering the first tooth, and 
 a first flange portion covering the first flange, the first flange portion having a first face that is in facing relationship with the first back insulation portion; 
   the second insulation portion includes
 a second back insulation portion covering the second annular back portion, 
 a second tooth portion covering the second tooth, and 
 a second flange portion covering the second flange, the second flange portion having a second face that is in facing relationship with the second back insulation portion; 
   the first face and the second face together substantially define a boundary plane, such that a cross-sectional slot area is defined between the first back insulation portion, the second back insulation portion, the first tooth portion, the second tooth portion, and the boundary plane;   the first coil and the second coil comprise a plurality of conductive wires arranged between the first tooth and the second tooth, the plurality of conductive wires defining a cross-sectional winding area within the cross-sectional slot area; and   a ratio of the cross-sectional winding area to the cross-sectional slot area is greater than or equal to 0.45.   
     
     
         10 . The electric motor of  claim 1 , wherein when the motor continuously draws 40 Amps of current, a time to the motor reaching a critical temperature is greater than or equal to 511 seconds. 
     
     
         11 . The electric motor of  claim 1 , wherein when the motor continuously draws 60 Amps of current, a time to the motor reaching a critical temperature is greater than or equal to 91 seconds. 
     
     
         12 . The electric motor of  claim 1 , wherein when the motor continuously draws 80 Amps of current, a time to the motor reaching a critical temperature is greater than or equal to 43 seconds. 
     
     
         13 . The electric motor of  claim 1 , wherein when the motor continuously draws 100 Amps of current, a time to the motor reaching a critical temperature is greater than or equal to 26 seconds. 
     
     
         14 . An electric motor comprising:
 a rotor; and   a stator including
 a back portion, 
 a tooth having a spoke portion extending radially inward from the back portion and a flange extending transverse to the spoke portion, such that a slot is defined between the flange and the back portion, and 
 a stator coil wound around the spoke portion of the tooth and within the slot in progressive turns including a first turn, a plurality of intermediate turns, and a final turn; 
   wherein the final turn of the stator coil has a greater cross-sectional length than a first turn of the stator coil; and   wherein the first turn and the final turn each have an equal cross-sectional width measured perpendicular to the cross-sectional length.   
     
     
         15 . The electric motor of  claim 14 , wherein the back portion is a first annular back portion, the tooth is a first tooth, the flange is a first flange, and the stator coil is a first coil; and
 wherein the stator further includes:
 a first stator segment including
 the first annular back portion, 
 the first tooth, 
 a first insulation portion at least partially covering the first annular back portion and the first tooth, and 
 the first coil, and 
 
 a second stator segment separate from the first stator segment and axially coupled to the first stator segment, the second stator segment including
 a second annular back portion, 
 a second tooth extending radially inward from the second annular back portion, 
 a second insulation portion at least partially covering the second annular back portion and the second tooth, and 
 a second coil wound around the second tooth. 
 
   
     
     
         16 . The electric motor of  claim 15 , wherein the first annular back portion and the second annular back portion are both ring-shaped. 
     
     
         17 . A method of manufacturing an electric motor, the method comprising:
 forming a first stator segment with a first annular back portion, a first tooth extending radially inward from the first annular back portion, and a first flange extending away from the first tooth;   applying a first layer of insulation around the first tooth;   applying a first stator coil around the first layer of insulation;   forming a second stator segment with a second annular back portion, a second tooth extending radially inward from the second annular back portion, and a second flange extending away from the second tooth;   applying a second layer of insulation around the second tooth;   applying a second stator coil around the second layer of insulation; and   axially coupling the first stator segment to the second stator segment.   
     
     
         18 . The method of  claim 17 , wherein the first layer of insulation includes:
 a first back insulation portion covering the first annular back portion,   a first tooth portion covering the first tooth, and   a first flange portion covering the first flange, the first flange portion having a first face that is in facing relationship with the first back insulation portion;   
       wherein the second layer of insulation includes:
 a second back insulation portion covering the second annular back portion, 
 a second tooth portion covering the second tooth, and 
 a second flange portion covering the second flange, the second flange portion having a second face that is in facing relationship with the second back insulation portion; 
 
       wherein the first face and the second face together substantially define a boundary plane, such that a cross-sectional slot area is defined between the first back insulation portion, the second back insulation portion, the first tooth portion, the second tooth portion, and the boundary plane; 
       wherein the first stator coil and the second stator coil comprise a plurality of conductive wires arranged between the first tooth and the second tooth, the plurality of conductive wires defining a cross-sectional winding area within the cross-sectional slot area; and 
       wherein a ratio of the cross-sectional winding area to the cross-sectional slot area is greater than or equal to 0.45. 
     
     
         19 . The method of  claim 17 , wherein applying the first stator coil around the first layer of insulation comprises:
 using a 3D printer to print a plurality of alternating layers of insulation and layers of electrically conductive metal around the first tooth;   coupling a first electrical connector to a first layer of the layers of electrically conductive metal; and   coupling a second electrical connector to a final layer of the layers of electrically conductive metal.   
     
     
         20 . The method of  claim 19 , wherein a first of the layers of insulation and a first of the layers of electrically conductive metal are printed simultaneously by the 3D printer.